Technique for reading bar codes
First Claim
1. A bar code apparatus for processing digitized bar code data stored electronically in bit map form and representative of a bar code having parallel bar code components including alternating dark bars and blank spaces carried on a light reflective surface, said bar code data being obtained by scanning said surface in lines along a primary scanning direction substantially perpendicular to the bar code components and at a resolution of a predetermined number of pixels per unit length to generate for a line of said pixels respective bar code signals having values related to the amount of light reflected by said dark bars and blank spaces, respectively, and scanning in a secondary scanning direction substantially perpendicular to said primary scanning direction to traverse a plurality of said scanning lines at a resolution of a predetermined number of lines per unit length, said bit map being produced from said bar code signals and having a plurality of bits arranged in rows, said rows corresponding, respectively, to the scanning lines, and the bits in each row corresponding to the pixels in a corresponding one of said scanning lines, the bit map bits having a bit value related to the bar code signal value of the corresponding pixels;
- said apparatus comprising;
memory means for storing assigned bar code component data related to a number of bits allotted, respectively, in a row of said bit map to said bar code components;
means for comparing the bit map with the stored bar code component data to identify said bar code components in said bit map; and
conversion means for providing from said identified bar code components a bar code reading result for converting the bar code to the message it represents.
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Accused Products
Abstract
A technique for reading a bar code representative of message information is stored electronically in bit-map form. The bit map is obtained by optically scanning a document carrying non-bar code information also to convert pixel information into bit information. A row is identified in the bit map which is the most likely one to pass through an area in the bit map containing bar code information. The data stored in the bit map is compared with assigned data corresponding to designated bar code components. Once such a row is identified, processing of rows above and below it in the bit map reveals whether rows more likely to agree with the coded message information can be found. Initially, a fast processing mode is selected involving processing of only a few rows to maximize processing speed in case acceptable data can be found. If acceptable bar code data is not found, then the processing is switched into a slow processing mode which involves processing of a greater number of rows. Once a row likely to contain the bar code data of interest is identified, the information it contains is converted into signals which are used for converting the coded bar code data into the message represented thereby.
87 Citations
52 Claims
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1. A bar code apparatus for processing digitized bar code data stored electronically in bit map form and representative of a bar code having parallel bar code components including alternating dark bars and blank spaces carried on a light reflective surface, said bar code data being obtained by scanning said surface in lines along a primary scanning direction substantially perpendicular to the bar code components and at a resolution of a predetermined number of pixels per unit length to generate for a line of said pixels respective bar code signals having values related to the amount of light reflected by said dark bars and blank spaces, respectively, and scanning in a secondary scanning direction substantially perpendicular to said primary scanning direction to traverse a plurality of said scanning lines at a resolution of a predetermined number of lines per unit length, said bit map being produced from said bar code signals and having a plurality of bits arranged in rows, said rows corresponding, respectively, to the scanning lines, and the bits in each row corresponding to the pixels in a corresponding one of said scanning lines, the bit map bits having a bit value related to the bar code signal value of the corresponding pixels;
- said apparatus comprising;
memory means for storing assigned bar code component data related to a number of bits allotted, respectively, in a row of said bit map to said bar code components; means for comparing the bit map with the stored bar code component data to identify said bar code components in said bit map; and conversion means for providing from said identified bar code components a bar code reading result for converting the bar code to the message it represents. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
- said apparatus comprising;
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16. Apparatus for determining a bar code from a bit map obtained by a plurality of optically scanned lines of a light reflective surface area, at least part of which carries said bar code having components including alternating dark bars and blank spaces representative of selected message information, and scanned with a resolution of a predetermined number of pixels per unit length to input data into said bit map related to light reflected by respective pixels of said surface, said bit map having a plurality of bits arranged in rows, said rows corresponding, respectively, to the scanning lines, and the bits in each row corresponding to the pixels in a corresponding one of said scanning lines, comprising:
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means for storing assigned bar code component data related to a number of bits allotted, respectively, in a row of said bit map to said bar components; means for designating at least two rows in said bit map; means for comparing the at least two designated rows with said assigned bar code component data to provide an identified bar code component signal; means coupled to the comparing means for identifying the longest string of consecutive bar code components for each of said designated rows; means for selecting whichever of said designated rows has the longest string of consecutive bar code components; and means coupled to the selecting means for obtaining a bar code reading result from the selected designated row for converting the bar code to said selected message information. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
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31. A bar code reading apparatus comprising:
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means for optically detecting a bar code with which selected message information has been converted into a coded version, said bar code having parallel bar code components including alternating dark bars and blank spaces carried on a light reflective surface, said detecting means scanning said surface in lines along a primary scanning direction substantially perpendicular to the bar code components and at a resolution of a predetermined number of pixels per unit length to generate for a line of said pixels respective bar code signals having values related to the amount of light reflected by said dark bars and blank spaces, respectively, said detecting means moving in a secondary scanning direction substantially perpendicular to said primary scanning direction to traverse a plurality of said scanning lines at a resolution of a predetermined number of lines per unit length; means coupled to the detecting means for producing from said bar code signals a bit map having a plurality of bits arranged in rows, said rows corresponding, respectively, to the scanning lines, and the bits in each row corresponding to the pixels in a corresponding one of said scanning lines, the bit map bits having a bit value related to the bar code signal value of the respective corresponding pixels; memory means for storing assigned bar code component data related to a number of bits allotted, respectively, in a row of said bit map to said bar code components; means for comparing the bit map with the stored bar code component data to identify said bar code components in said bit map; and conversion means for providing from said identified bar code components a bar code reading result for converting the bar code to said selected message information. - View Dependent Claims (32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49)
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50. A method for processing digitized bar code data stored electronically in bit map form and representative of a bar code having parallel bar code components including alternating dark bars and blank spaces carried on a light reflective surface, said bar code data being obtained by scanning said surface in lines along a primary scanning direction substantially perpendicular to the bar code components and at a resolution of a predetermined number of pixels per unit length to generate for a line of said pixels respective bar code signals having values related to the amount of light reflected by said dark bars and blank spaces, respectively, and scanning in a secondary scanning direction substantially perpendicular to said primary scanning direction to traverse a plurality of said scanning lines at a resolution of a predetermined number of lines per unit length, said bit map being produced from said bar code signals and having a plurality of bits arranged in rows, said rows corresponding, respectively, to the scanning lines, and the bits in each row corresponding to the pixels in a corresponding one of said scanning lines, the bit map bits having a bit value related to the bar code signal value of the corresponding pixels;
- said method comprising the steps of;
storing assigned bar code component data related to a number of bits allotted, respectively, in a row of said bit map to said bar code components; comparing the bit map with the stored bar code component data to identify said bar code components in said bit map; and providing from said identified bar code components a bar code reading result for converting the bar code to the message it represents.
- said method comprising the steps of;
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51. A method for determining a bar code from a bit map obtained by a plurality of optically scanned lines of a light reflective surface area, at least part of which carries said bar code having components including alternating dark bars and blank spaces representative of selected message information, and scanned with a resolution of a predetermined number of pixels per unit length to input data into said bit map related to light reflected by respective pixels of said surface, said bit map having a plurality of bits arranged in rows, said rows corresponding, respectively, to the scanning lines, and the bits in each row corresponding to the pixels in a corresponding one of said scanning lines, comprising the steps of:
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storing assigned bar code component data related to a number of bits allotted, respectively, in a row of said bit map to said bar components; designating at least two rows in said bit map; comparing the at least two designated rows with said assigned bar code component data to provide an identified bar code component signal; identifying the longest string of consecutive bar code components for each of said designated rows; selecting whichever of said designated rows has the longest string of consecutive bar code components; and obtaining a bar code reading result from the selected designated row for converting the bar code to said selected message information.
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52. A method for reading a bar code comprising the steps of:
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optically detecting a bar code with which selected message information has been converted into a coded version, said bar code having parallel bar code components including alternating dark bars and blank spaces carried on a light reflective surface, said surface being scanned in lines along a primary scanning direction substantially perpendicular to the bar code components and at a resolution of a predetermined number of pixels per unit length to generate for a line of said pixels respective bar code signals having values related to the amount of light reflected by said dark bars and blank spaces, respectively, said scanning also moving in a secondary scanning direction substantially perpendicular to said primary scanning direction to traverse a plurality of said scanning lines at a resolution of a predetermined number of lines per unit length; producing from said bar code signals a bit map having a plurality of bits arranged in rows, said rows corresponding, respectively, to the scanning lines, and the bits in each row corresponding to the pixels in a corresponding one of said scanning lines, the bit map bits having a bit value related to the bar code signal value of the respective corresponding pixels; storing assigned bar code component data related to a number of bits allotted, respectively, in a row of said bit map to said bar code components; comparing the bit map with the stored bar code component data to identify said bar code components in said bit map; and providing from said identified bar code components a bar code reading result for converting the bar code to said selected message information.
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Specification